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CC BY-NC-ND 4.0 · Geburtshilfe Frauenheilkd 2022; 82(02): 226-234
DOI: 10.1055/a-1727-9672
GebFra Science
Original Article

Prevalence of SARS-CoV-2 in Pregnant Women Assessed by RT-PCR in Franconia, Germany: First Results of the SCENARIO Study (SARS-CoV-2 prEvalence in pregNAncy and at biRth In FrancOnia)

Prävalenz von SARS-CoV-2 bei schwangeren Frauen ermittelt durch RT-PCR in Franken, Deutschland: erste Ergebnisse der SCENARIO-Studie (SARS-CoV-2 prEvalence in pregNAncy and at biRth In FrancOnia)
Alexander Hein
1   Department of Gynaecology and Obstetrics, Erlangen University Hospital, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
,
Sven Kehl
1   Department of Gynaecology and Obstetrics, Erlangen University Hospital, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
,
Lothar Häberle
1   Department of Gynaecology and Obstetrics, Erlangen University Hospital, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
,
Carsten Tiemann
2   MVZ Labor Krone GbR, Bad Salzuflen, Germany
,
Rebecca Peuker
1   Department of Gynaecology and Obstetrics, Erlangen University Hospital, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
,
Denise Mereutanu
1   Department of Gynaecology and Obstetrics, Erlangen University Hospital, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
,
Florian M. Stumpfe
1   Department of Gynaecology and Obstetrics, Erlangen University Hospital, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
,
Florian Faschingbauer
1   Department of Gynaecology and Obstetrics, Erlangen University Hospital, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
,
Kirstin Meyer-Schlinkmann
2   MVZ Labor Krone GbR, Bad Salzuflen, Germany
,
Martin C. Koch
3   Department of Gynaecology and Obstetrics, ANregiomed Klinikum Ansbach, Ansbach, Germany
,
Franz Kainer
4   Department of Gynaecology and Obstetrics, Klinik Hallerwiese, Nürnberg, Germany
,
Ulf Dammer
5   Department of Gynaecology and Obstetrics, St. Theresien-Krankenhaus, Nürnberg, Germany
,
Hanna Philipp
6   Department of Gynaecology and Obstetrics, REGIOMED Klinikum Coburg, Coburg, Germany
,
Carolin Kladt
7   Department of Gynaecology and Obstetrics, Clinic Bayreuth, Bayreuth, Germany
,
Michael G. Schrauder
8   Department of Gynaecology and Obstetrics, Klinikum Aschaffenburg-Alzenau, Aschaffenburg, Germany
,
Stefan Weingärtler
9   Department of Gynaecology and Obstetrics, Klinikum Forchheim-Fränkische Schweiz, Forchheim, Germany
,
Volker Hanf
10   Department of Gynaecology and Obstetrics, Klinikum Fürth, Fürth, Germany
,
Arndt Hartmann
11   Institute of Pathology, Erlangen University Hospital, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
,
Matthias Rübner
1   Department of Gynaecology and Obstetrics, Erlangen University Hospital, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
,
Holm Schneider
12   Department of Pediatrics, Erlangen University Hospital, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
,
Jos Lelieveld
13   Max-Planck Institut für Chemie, Mainz, Germany
,
Matthias W. Beckmann
1   Department of Gynaecology and Obstetrics, Erlangen University Hospital, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
,
Lena A. Wurmthaler
1   Department of Gynaecology and Obstetrics, Erlangen University Hospital, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
,
Peter A. Fasching
1   Department of Gynaecology and Obstetrics, Erlangen University Hospital, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
,
Michael O. Schneider
1   Department of Gynaecology and Obstetrics, Erlangen University Hospital, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
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Abstract

Purpose Detection of SARS-CoV-2-infected pregnant women admitted to maternity units during a pandemic is crucial. In addition to the fact that pregnancy is a risk factor for severe COVID-19 and that medical surveillance has to be adjusted in infected women and their offspring, knowledge about infection status can provide the opportunity to protect other patients and healthcare workers against virus transmission. The aim of this prospective observational study was to determine the prevalence of SARS-CoV-2 infection among pregnant women in the hospital setting.

Material and Methods All eligible pregnant women admitted to the nine participating hospitals in Franconia, Germany, from 2 June 2020 to 24 January 2021 were included. COVID-19-related symptoms, secondary diseases and pregnancy abnormalities were documented. SARS-CoV-2 RNA was detected by RT-PCR from nasopharyngeal swabs. The prevalence of acute SARS-CoV-2 infection was estimated by correcting the positive rate using the Rogan–Gladen method. The risk of infection for healthcare workers during delivery was estimated using a risk calculator.

Results Of 2414 recruited pregnant women, six were newly diagnosed RT-PCR positive for SARS-CoV-2, which yielded a prevalence of SARS-CoV-2 infection of 0.26% (95% CI, 0.10 – 0.57%). Combining active room ventilation and wearing FFP2 masks showed an estimated reduction of risk of infection for healthcare workers in the delivery room to < 1%.

Conclusions The prevalence of newly diagnosed SARS-CoV-2 infection during pregnancy in this study is low. Nevertheless, a systematic screening in maternity units during pandemic situations is important to adjust hygienic and medical management. An adequate hygienic setting can minimise the calculated infection risk for medical healthcare workers during patientsʼ labour.

Zusammenfassung

Zielsetzung Das Erkennen von SARS-CoV-2-Infektionen bei schwangeren Frauen, die während der Pandemie in eine geburtshilfliche Abteilung aufgenommen werden, ist essenziell. Bekanntlich stellt die Schwangerschaft einen Risikofaktor für die Entwicklung einer schweren COVID-19-Erkrankung dar, und die medizinische Überwachung von infizierten Frauen und ihren Kindern muss dementsprechend angepassst werden. Das Wissen um den Infektionsstatus von Patientinnen macht es möglich, andere Patientinnen und das medizinische Fachpersonal vor einer Übertragung des Virus zu schützen. Ziel dieser prospektiven Beobachungsstudie war es, die Prävalenz von SARS-CoV-2-Infektionen bei schwangeren Frauen im Krankenhaus zu bestimmen.

Material und Methoden Alle schwangeren Frauen, die in einem der 9 teilnehmenden Krankenhäuser in Franken, Deutschland, zwischen dem 2. Juni 2020 und dem 24. Januar 2021 vorstellig waren, wurden in die Studie aufgenommen. COVID-19-bedingte Symptome, sekundäre Erkrankungen und Schwangerschaftsanomalien wurden dokumentiert. Die mit nasopharyngealen Abstrichen entnommene SARS-CoV-2-RNA wurde mittels RT-PCR detektiert. Ausgehend von der Rate positiver Fälle wurde die wahre Prävalenz von akuten SARS-CoV-2-Infektionen mit der Rogan–Gladen-Methode geschätzt. Das Infektionsrisiko für das medizinische Fachpersonal während der Entbindung wurde unter Zuhilfenahme eines Risikoberechners geschätzt.

Ergebnisse Bei 6 von insgesamt 2414 in die Studie rekrutierten schwangeren Frauen wurde nach einer RT-PCR-Diagnostik eine SARS-CoV-2-Infektion erstdiagnostiziert. Das entspricht einer Prävalenz von SARS-CoV-2-Infektionen von 0,26% (95%-KI 0,10 – 0,57%). Eine aktive Raumbelüftung in Kombination mit dem Tragen von FFP2-Masken verringerte das geschätzte Risiko einer Infektion für das im Entbindungssaal tätige medizinische Fachpersonal auf < 1%.

Schlussfolgerungen Die Prävalenz einer neuen SARS-CoV-2-Infektion während der Schwangerschaft war in dieser Studie gering. Trotzdem ist es wichtig, während der Pandemie systematische Untersuchungen in geburtshilflichen Abteilungen durchzuführen, um die Hygienemaßnahmen und die medizinische Betreuung im Falle einer Infektion anzupassen. Angemessene Infektionsschutzmaßnahmen können das kalkulierte Risiko für das medizinische Fachpersonal während der Geburtsbetreuung minimieren.

Key words

SARS-CoV-2 - COVID-19 - pregnancy - prevalence - infection

Schlüsselwörter

SARS-CoV-2 - COVID-19 - Schwangerschaft - Prävalenz - Infektion

Supplements

    Questionnaire: Self reporting questionnaire for COVID-19-related symptoms, secondary diseases and abnormalities during pregnancy.

    Figure S1: Settings for the calculation of infection risk for medical staff in the delivery room. The parameters presented in the Figure are estimated average times, speech volume, speaking/breathing ratio and respiration rate of the mother in a hypothetical normal labour of 11.6 hours in the delivery room. Estimated length of stay in the delivery room of partner, midwife and obstetrician is also shown for every stage of delivery.

    Figure S2: Histogramm of gestational weeks at study entry.

  • Supporting Information


Publication History

Received: 11 November 2021

Accepted after revision: 22 December 2021

Article published online:
11 February 2022

© 2022. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commecial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/)

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  • References

  • 1 Wu Z, McGoogan JM. Asymptomatic and Pre-Symptomatic COVID-19 in China. Infect Dis Poverty 2020; 9: 72
    CrossrefPubMedGoogle Scholar
  • 2 Wu Z, McGoogan JM. Characteristics of and Important Lessons From the Coronavirus Disease 2019 (COVID-19) Outbreak in China: Summary of a Report of 72314 Cases From the Chinese Center for Disease Control and Prevention. JAMA 2020; 323: 1239-1242
    CrossrefPubMedGoogle Scholar
  • 3 Lu R, Zhao X, Li J. et al. Genomic characterisation and epidemiology of 2019 novel coronavirus: implications for virus origins and receptor binding. Lancet 2020; 395: 565-574
    CrossrefPubMedGoogle Scholar
  • 4 Stumpfe FM, Titzmann A, Schneider MO. et al. SARS-CoV-2 Infection in Pregnancy – a Review of the Current Literature and Possible Impact on Maternal and Neonatal Outcome. Geburtshilfe Frauenheilkd 2020; 80: 380-390
    Article in Thieme ConnectPubMedGoogle Scholar
  • 5 Knight M, Bunch K, Vousden N. et al. Characteristics and outcomes of pregnant women admitted to hospital with confirmed SARS-CoV-2 infection in UK: national population based cohort study. BMJ 2020; 369: m2107
    CrossrefPubMedGoogle Scholar
  • 6 Pettirosso E, Giles M, Cole S. et al. COVID-19 and pregnancy: A review of clinical characteristics, obstetric outcomes and vertical transmission. Aust N Z J Obstet Gynaecol 2020; 60: 640-659
    CrossrefPubMedGoogle Scholar
  • 7 Ellington S, Strid P, Tong VT. et al. Characteristics of Women of Reproductive Age with Laboratory-Confirmed SARS-CoV-2 Infection by Pregnancy Status – United States, January 22-June 7, 2020. MMWR Morb Mortal Wkly Rep 2020; 69: 769-775
    CrossrefPubMedGoogle Scholar
  • 8 Zambrano LD, Ellington S, Strid P. et al. Update: Characteristics of Symptomatic Women of Reproductive Age with Laboratory-Confirmed SARS-CoV-2 Infection by Pregnancy Status – United States, January 22-October 3, 2020. MMWR Morb Mortal Wkly Rep 2020; 69: 1641-1647
    CrossrefPubMedGoogle Scholar
  • 9 Capobianco G, Saderi L, Aliberti S. et al. COVID-19 in pregnant women: A systematic review and meta-analysis. Eur J Obstet Gynecol Reprod Biol 2020; 252: 543-558
    CrossrefPubMedGoogle Scholar
  • 10 Antoun L, Taweel NE, Ahmed I. et al. Maternal COVID-19 infection, clinical characteristics, pregnancy, and neonatal outcome: A prospective cohort study. Eur J Obstet Gynecol Reprod Biol 2020; 252: 559-562
    CrossrefPubMedGoogle Scholar
  • 11 Khalil A, Kalafat E, Benlioglu C. et al. SARS-CoV-2 infection in pregnancy: A systematic review and meta-analysis of clinical features and pregnancy outcomes. EClinicalMedicine 2020; 25: 100446
    CrossrefPubMedGoogle Scholar
  • 12 Diriba K, Awulachew E, Getu E. The effect of coronavirus infection (SARS-CoV-2, MERS-CoV, and SARS-CoV) during pregnancy and the possibility of vertical maternal-fetal transmission: a systematic review and meta-analysis. Eur J Med Res 2020; 25: 39
    CrossrefPubMedGoogle Scholar
  • 13 Prochaska E, Jang M, Burd I. COVID-19 in pregnancy: Placental and neonatal involvement. Am J Reprod Immunol 2020; 84: e13306
    CrossrefPubMedGoogle Scholar
  • 14 Delahoy MJ, Whitaker M, OʼHalloran A. et al. Characteristics and Maternal and Birth Outcomes of Hospitalized Pregnant Women with Laboratory-Confirmed COVID-19 – COVID-NET, 13 States, March 1-August 22, 2020. MMWR Morb Mortal Wkly Rep 2020; 69: 1347-1354
    CrossrefPubMedGoogle Scholar
  • 15 Jering KS, Claggett BL, Cunningham JW. et al. Clinical Characteristics and Outcomes of Hospitalized Women Giving Birth With and Without COVID-19. JAMA Intern Med 2021; 181: 714-717
    CrossrefPubMedGoogle Scholar
  • 16 Villar J, Ariff S, Gunier RB. et al. Maternal and Neonatal Morbidity and Mortality Among Pregnant Women With and Without COVID-19 Infection: The INTERCOVID Multinational Cohort Study. JAMA Pediatr 2021; 175: 817-826
    CrossrefPubMedGoogle Scholar
  • 17 Allotey J, Stallings E, Bonet M. et al. Clinical manifestations, risk factors, and maternal and perinatal outcomes of coronavirus disease 2019 in pregnancy: living systematic review and meta-analysis. BMJ 2020; 370: m3320
    CrossrefPubMedGoogle Scholar
  • 18 Patane L, Morotti D, Giunta MR. et al. Vertical transmission of coronavirus disease 2019: severe acute respiratory syndrome coronavirus 2 RNA on the fetal side of the placenta in pregnancies with coronavirus disease 2019-positive mothers and neonates at birth. Am J Obstet Gynecol MFM 2020; 2: 100145
    CrossrefPubMedGoogle Scholar
  • 19 Dong L, Tian J, He S. et al. Possible Vertical Transmission of SARS-CoV-2 From an Infected Mother to Her Newborn. JAMA 2020; 323: 1846-1848
    PubMedGoogle Scholar
  • 20 Zeng L, Xiao T, Zhou W. Vertical Transmission of Severe Acute Respiratory Syndrome Coronavirus 2 From the Mother to the Infant-Reply. JAMA Pediatr 2020; 174: 1008-1009
    CrossrefPubMedGoogle Scholar
  • 21 Zamaniyan M, Ebadi A, Aghajanpoor S. et al. Preterm delivery, maternal death, and vertical transmission in a pregnant woman with COVID-19 infection. Prenat Diagn 2020; 40: 1759-1761
    CrossrefPubMedGoogle Scholar
  • 22 Raschetti R, Vivanti AJ, Vauloup-Fellous C. et al. Synthesis and systematic review of reported neonatal SARS-CoV-2 infections. Nat Commun 2020; 11: 5164
    Google Scholar
  • 23 Fenizia C, Biasin M, Cetin I. et al. Analysis of SARS-CoV-2 vertical transmission during pregnancy. Nat Commun 2020; 11: 5128
    CrossrefPubMedGoogle Scholar
  • 24 Woodworth KR, Olsen EO, Neelam V. et al. Birth and Infant Outcomes Following Laboratory-Confirmed SARS-CoV-2 Infection in Pregnancy – SET-NET, 16 Jurisdictions, March 29-October 14, 2020. MMWR Morb Mortal Wkly Rep 2020; 69: 1635-1640
    CrossrefPubMedGoogle Scholar
  • 25 Walker KF, OʼDonoghue K, Grace N. et al. Maternal transmission of SARS-COV-2 to the neonate, and possible routes for such transmission: a systematic review and critical analysis. BJOG 2020; 127: 1324-1336
    CrossrefPubMedGoogle Scholar
  • 26 Mand N, Iannaccone A, Longardt AC. et al. CRONOS Network; CRONOS-Network. Neonatal outcome following maternal infection with SARS-CoV-2 in Germany: COVID-19-Related Obstetric and Neonatal Outcome Study (CRONOS). Arch Dis Child Fetal Neonatal Ed 2021; DOI: 10.1136/archdischild-2021-322100.
    CrossrefPubMedGoogle Scholar
  • 27 Gale C, Quigley MA, Placzek A. et al. Characteristics and outcomes of neonatal SARS-CoV-2 infection in the UK: a prospective national cohort study using active surveillance. Lancet Child Adolesc Health 2021; 5: 113-121
    CrossrefPubMedGoogle Scholar
  • 28 Sutton D, Fuchs K, DʼAlton M. et al. Universal Screening for SARS-CoV-2 in Women Admitted for Delivery. N Engl J Med 2020; 382: 2163-2164
    CrossrefPubMedGoogle Scholar
  • 29 Prabhu M, Cagino K, Matthews KC. et al. Pregnancy and postpartum outcomes in a universally tested population for SARS-CoV-2 in New York City: a prospective cohort study. BJOG 2020; 127: 1548-1556
    CrossrefPubMedGoogle Scholar
  • 30 Grossi E, Agnoli B, Baldini M. et al. Universal Sars-Cov-2 Screening in Pregnant Women: Experience from the Italian Epidemic Outbreak. Acta Biomed 2021; 92 (S2): e2021001
    PubMedGoogle Scholar
  • 31 Diaz-Corvillon P, Monckeberg M, Barros A. et al. Routine screening for SARS CoV-2 in unselected pregnant women at delivery. PLoS One 2020; 15: e0239887
    CrossrefPubMedGoogle Scholar
  • 32 German Federal Statistical Office (Destatis). Kreisfreie Städte und Landkreise nach Fläche, Bevölkerung und Bevölkerungsdichte am 31.12.2020. 2021. Accessed May 01, 2021 at: https://www.destatis.de
    Google Scholar
  • 33 Bavarian State Office for Statistics (LfStat). Statistik der Geburten. 2021. Accessed May 01, 2021 at: https://www.statistikdaten.bayern.de/
    Google Scholar
  • 34 WHO. Laboratory testing for coronavirus disease (COVID-19) in suspected human cases. 2020. Accessed May 01, 2021 at: https://apps.who.int/iris/rest/bitstreams/1272454/retrieve
    Google Scholar
  • 35 Streeck H, Schulte B, Kummerer BM. et al. Infection fatality rate of SARS-CoV2 in a super-spreading event in Germany. Nat Commun 2020; 11: 5829
    CrossrefPubMedGoogle Scholar
  • 36 Rogan WJ, Gladen B. Estimating prevalence from the results of a screening test. Am J Epidemiol 1978; 107: 71-76
    CrossrefPubMedGoogle Scholar
  • 37 Corman VM, Landt O, Kaiser M. et al. Detection of 2019 novel coronavirus (2019-nCoV) by real-time RT-PCR. Euro Surveill 2020; 25: 2000045
    Google Scholar
  • 38 Lelieveld J, Helleis F, Borrmann S. et al. Model Calculations of Aerosol Transmission and Infection Risk of COVID-19 in Indoor Environments. Int J Environ Res Public Health 2020; 17: 8114
    CrossrefPubMedGoogle Scholar
  • 39 Melchior H, Kurch-Bek D, Mund M. The Prevalence of Gestational Diabetes. Dtsch Arztebl Int 2017; 114: 412-418
    CrossrefPubMedGoogle Scholar
  • 40 Robert Koch Institute (RKI). COVID-19 Datenhub. 2021. Accessed May 01, 2021 at: https://npgeo-corona-npgeo-de.hub.arcgis.com/
    Google Scholar
  • 41 Young BE, Ong SWX, Ng LFP. et al. Singapore 2019 Novel Coronavirus Outbreak Research team. Viral Dynamics and Immune Correlates of Coronavirus Disease 2019 (COVID-19) Severity. Clin Infect Dis 2021; 73: e2932-e2942 DOI: 10.1093/cid/ciaa1280.
    CrossrefPubMedGoogle Scholar
  • 42 Khalil A, Hill R, Ladhani S. et al. COVID-19 screening of health-care workers in a London maternity hospital. Lancet Infect Dis 2021; 21: 23-24
    CrossrefPubMedGoogle Scholar
  • 43 Zollkau J, Baier M, Scherag A. et al. [Period Prevalence of SARS-CoV-2 in an Unselected Sample of Pregnant Women in Jena, Thuringia]. Z Geburtshilfe Neonatol 2020; 224: 194-198
    Article in Thieme ConnectPubMedGoogle Scholar
  • 44 Xu R, Pauley TA, Missfelder-Lobos H. et al. Samba II PCR testing for COVID-19 in pregnant women: a retrospective cohort study and literature review. BMC Pregnancy Childbirth 2021; 21: 212
    CrossrefPubMedGoogle Scholar
  • 45 Saviron-Cornudella R, Villalba A, Esteban LM. et al. Screening of severe acute respiratory syndrome coronavirus-2 infection during labor and delivery using polymerase chain reaction and immunoglobulin testing. Life Sci 2021; 271: 119200
    CrossrefPubMedGoogle Scholar
  • 46 Piekarski P, Sateja M, Maciejewski T. et al. No COVID-19 Cases Detected Between April and September 2020 After Screening All 838 Admissions to a Maternity Unit in Poland. Med Sci Monit 2021; 27: e929123
    CrossrefPubMedGoogle Scholar
  • 47 Khalil A, Hill R, Ladhani S. et al. Severe acute respiratory syndrome coronavirus 2 in pregnancy: symptomatic pregnant women are only the tip of the iceberg. Am J Obstet Gynecol 2020; 223: 296-297
    CrossrefPubMedGoogle Scholar
  • 48 Longardt AC, Winkler VP, Pecks U. [SARS-CoV-2 and Perinatal Aspects]. Z Geburtshilfe Neonatol 2020; 224: 181-186
    Article in Thieme ConnectPubMedGoogle Scholar
  • 49 Miller ES, Grobman WA, Sakowicz A. et al. Clinical Implications of Universal Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Testing in Pregnancy. Obstet Gynecol 2020; 136: 232-234
    CrossrefPubMedGoogle Scholar
  • 50 Massarotti C, Adriano M, Cagnacci A. et al. Asymptomatic SARS-CoV-2 infections in pregnant patients in an Italian city during the complete lockdown. J Med Virol 2021; 93: 1758-1760
    CrossrefPubMedGoogle Scholar
  • 51 Tanacan A, Erol SA, Turgay B. et al. The rate of SARS-CoV-2 positivity in asymptomatic pregnant women admitted to hospital for delivery: Experience of a pandemic center in Turkey. Eur J Obstet Gynecol Reprod Biol 2020; 253: 31-34
    CrossrefPubMedGoogle Scholar
  • 52 Maru S, Patil U, Carroll-Bennett R. et al. Universal screening for SARS-CoV-2 infection among pregnant women at Elmhurst Hospital Center, Queens, New York. PLoS One 2020; 15: e0238409
    CrossrefPubMedGoogle Scholar
  • 53 Pecks U, Kuschel B, Mense L. et al. Pregnancy and SARS-CoV-2 Infection in Germany-the CRONOS Registry. Dtsch Arztebl Int 2020; 117: 841-842
    Google Scholar
  • 54 Zollkau J, Hagenbeck C, Hecher K. et al. [Update on Recommendations for SARS-CoV-2/COVID-19 During Pregnancy, Birth and Childbed]. Z Geburtshilfe Neonatol 2020; 224: 217-222
    Article in Thieme ConnectPubMedGoogle Scholar
  • 55 Ade C, Pum J, Abele I. et al. Analysis of cycle threshold values in SARS-CoV-2-PCR in a long-term study. J Clin Virol 2021; 138: 104791
    CrossrefPubMedGoogle Scholar
  • 56 Robert Koch Institute (RKI). Antikörperstudien in der Allgemeinbevölkerung. 2020. Accessed May 01, 2021 at: https://www.rki.de/DE/Content/InfAZ/N/Neuartiges_Coronavirus/AK-Studien/AKS_Allgemein.html
    Google Scholar